Imaging element and electronic device

Abstract

The present technique relates to an imaging element and an electronic device that can extend a dynamic range. The imaging element includes: a first photoelectric conversion unit that is provided in a semiconductor substrate and generates a charge corresponding to the amount of light; a second photoelectric conversion unit having a smaller light-receiving area than the first photoelectric conversion unit; a first inter-pixel isolation portion that surrounds a unit pixel including the first photoelectric conversion unit and the second photoelectric conversion unit; and a second inter-pixel isolation portion provided between the first photoelectric conversion unit and the second photoelectric conversion unit, wherein the first inter-pixel isolation portion and the second inter-pixel isolation portion are each configured with a trench penetrating the semiconductor substrate. The present technique can be applied to an imaging element including a large pixel and a small pixel.

What is claimed is: 
     
         1 . An imaging element, comprising: a first photoelectric conversion unit that is provided in a semiconductor substrate and generates a charge corresponding to an amount of light;
 a second photoelectric conversion unit having a smaller light-receiving area than the first photoelectric conversion unit;   a first inter-pixel isolation portion that surrounds a unit pixel including the first photoelectric conversion unit and the second photoelectric conversion unit; and a second inter-pixel isolation portion provided between the first photoelectric conversion unit and the second photoelectric conversion unit,   wherein the first inter-pixel isolation portion and the second inter-pixel isolation portion are each configured with a trench penetrating the semiconductor substrate.   
     
     
         2 . The imaging element according to  claim 1 , wherein the trench is filled with an insulator. 
     
     
         3 . The imaging element according to  claim 1 , wherein one or more transistors and a contact are disposed in a region where the second photoelectric conversion unit is formed in plan view. 
     
     
         4 . The imaging element according to  claim 1 , wherein a capacitor is connected to the second photoelectric conversion unit. 
     
     
         5 . The imaging element according to  claim 1 , wherein the unit pixel further includes an element isolation region that separates elements, and
 the element isolation region is configured with a trench not penetrating the semiconductor substrate.   
     
     
         6 . The imaging element according to  claim 1 , wherein the first photoelectric conversion unit is L-shaped in plan view,
 the second photoelectric conversion unit is square-shaped, and   a combination of the first photoelectric conversion unit and the second photoelectric conversion unit is square-shaped.   
     
     
         7 . The imaging element according to  claim 1 , wherein two sides of a gate of at least one of a plurality of transistors constituting the unit pixel are located on the first inter-pixel isolation portion and the second inter-pixel isolation portion in plan view. 
     
     
         8 . The imaging element according to  claim 1 , wherein two sides of a gate of an amplification transistor are located on the first inter-pixel isolation portion and the second inter-pixel isolation portion in plan view. 
     
     
         9 . The imaging element according to  claim 8 , wherein the two sides are parallel to a line connecting a source and a drain of the amplification transistor. 
     
     
         10 . The imaging element according to  claim 1 , further comprising a first lens disposed on the first photoelectric conversion unit; and
 a second lens disposed on the second photoelectric conversion unit,   wherein   the first lens and the second lens are identical in size.   
     
     
         11 . The imaging element according to  claim 1 , further comprising a first lens disposed on the first photoelectric conversion unit; and
 a second lens disposed on the second photoelectric conversion unit,   wherein   the first lens and the second lens have different sizes.   
     
     
         12 . The imaging element according to  claim 11 , wherein the first lens and the second lens that are disposed in the unit pixel are placed in contact with each other, and
 the second lens disposed in a first unit pixel and the first lens disposed in a second unit pixel adjacent to the first unit pixel are not placed in contact with each other.   
     
     
         13 . The imaging element according to  claim 12 , wherein the first lens in contact with the second lens is oval. 
     
     
         14 . The imaging element according to  claim 11 , wherein the plurality of square-shaped first lenses are disposed on the first photoelectric conversion unit. 
     
     
         15 . The imaging element according to  claim 11 , wherein the second lens disposed in a first unit pixel is placed in contact with the first lens disposed in the first unit pixel and the first lens disposed in a second unit pixel adjacent to the first unit pixel. 
     
     
         16 . The imaging element according to  claim 11 , wherein the first lens has a different size for each color of a placed color filter. 
     
     
         17 . The imaging element according to  claim 1 , wherein a light shielding film provided on the second inter-pixel isolation portion is located at a position shifted toward the second photoelectric conversion unit. 
     
     
         18 . The imaging element according to  claim 1 , wherein the trench of each of the first inter-pixel isolation portion and the second inter-pixel isolation portion includes a fixed charge film therein, and
 each of the first photoelectric conversion unit and the second photoelectric conversion unit has an n-type impurity region in contact with the trench.   
     
     
         19 . An electronic device, comprising an imaging element and a processing unit that processes a signal from the imaging element, the imaging element including: a first photoelectric conversion unit that is provided in a semiconductor substrate and generates a charge corresponding to an amount of light;
 a second photoelectric conversion unit having a smaller light-receiving area than the first photoelectric conversion unit;   a first inter-pixel isolation portion that surrounds a unit pixel including the first photoelectric conversion unit and the second photoelectric conversion unit; and a second inter-pixel isolation portion provided between the first photoelectric conversion unit and the second photoelectric conversion unit,   wherein the first inter-pixel isolation portion and the second inter-pixel isolation portion are each configured with a trench penetrating the semiconductor substrate.